This invention relates to a ball joint including a ball member having a ball end and a socket member having a recess for pivotally receiving the ball end of the ball member.
Usually, the diameter of the opening of the recess is larger than that of the ball end of the ball member, and an annular retaining ring is fitted in the recess for preventing the ball end from escaping out. In its normal uncompressed condition, the outer diameter of the retaining ring is larger than the diameter of the opening of the recess and the inner diameter of the retaining ring is smaller than the diameter of the ball end so that the ball end is effectively retained in the recess. However, there has been provided a substantial amount of circumferential gap in the retaining ring so as to permit the retaining ring to be compressed with the diameter thereof being reduced in inserting the retaining ring into the recess. However, when the ball member is strongly pulled in the direction of escape from the recess, the retaining ring may sometimes be compressed in the direction which reduces the gap thereby reducing the diameter and allowing the ball member to escape from the recess. Thus, the prior art ball joint has a shortcoming that the connection between the ball member and the socket member is not reliable.